Electrical production of heat for cooking and other purposes.



A. F. BERRY. ELECTRICAL PRODUCTION OF HEAT FOR COOKING AND OTHER PURPOSES.

APPLICATION FILED AUG. 9, 1906.

Patented Aug. 24, 1909.

4 snnnrr's-snnnr 1.

A. F. BERRY. ELECTRICAL PRODUCTION OF HEAT FOR COOKING AND OTHER PURPOSES. APPLICATION FILED AUG. 9, 1906.

2,242. Patented Aug. 24,1909

4 BHEETS-SHEET 2.

A. F. BERRY. ELECTRICAL PRODUCTION OF HEAT FOR 0001mm AND OTHER PURPOSES. APPLICATION FILED AUG. 9, I906.

932,242. Patented Aug. 24, 1909.

4 8HEETSSHEET 3.

A. F. BERRY. ELECTRICAL PBODUGTIOH OF HEAT FOB COOKING AND OTHER PURPOSES. APPLICATION IILED AUG. 9, 1906.

932,242. Patented Aug. 24, 1909.

4 SHEETS-SHEET 4.

duction of hca tiby electrical means and it? other-Puraoses of which the followin is a l l 7 b -pro;duced inasimple, ,safe and economica also to provide electrical heating apparatusi by the actionof analternating current of t able induction drop in-such asecondary cir-l cult and irregular results would be obta1ned,i

:secondary. conductor or each such conducto 5 ductor or conductors so as to tan-mun 1 STiSzTES rA NT crater;

ARTHUR FRANCIS BERRYIGF EE'IlINQ-ENGLAND.

ELECTRICAL PRODUCTION OF HEAT FQR COOKI NG AND OTHER PURPOSES.

Application filed Ahgust 9,

To all whom it may concern:

Be it known that I, ARTHUR FRANCIS BERRY, a subject of the King of Great Britain and Ireland, residing at Ealing, in the county of Middlesex, England, have inventl ed lnnirovements'in or Relating to the Electrical Production of Heat for Cooking andi specification. i 1 I Til1S.ll1vQllilXO11 has reference to the prohas for objectlto enable suc'h heat to bef m'annerfor domestic and other purposes, and

of simple construction, suitable for various useful purposes. For this purposein apparatus according thereto, the required heat is produced by alternating current of great strength and low voltage induced in a solid metallic secondary conductoror conductors comparatively small strength and hi h-voltage in a primary conductor or con uctors.

'tacts if, .tl18.:0l1'0ult of'the secondary con ducterzca-rryinglarge currents at low vol I tage, say'. currents of theord'er ofone' thou-V sand amperes and upward-at about one or; two volts, were made and broken bya switch device upon putting the apparatus inand? out of use, and as there would be a consideri if the switch contacts for closing the said? secondary circult did not make practically perfect connection with each other, the said;

is, according to this invention perinanentl closed upon itself. Also, the secondary con ductor, or each secondary .conductor,",is or? may advantageously be'arranged on,- Within? or in proximity to the primary, conductor or: conductors so a's. .to be under the direct inductive action thereof. 'Als'o, such secondary; conductor, or each secondary 'conductor,= owing to the low voltage therein, may be bare I or uninsulated but may, where necessary, be specially insulated from the primary con-{ protect the lat-1 ter against undue heating... i 2

The invention consists in various novel features of constructionand in combinations and arrangements of parts all as hereinafter more particularly described.

Specification of Izetters Patent.

i906 Serial No. 329,876.

l H In apparatus according thereto, liquid or other substance contained in a kettle, saucepan, boiler, oven or other vessel or chamber (hereinafter called a vessel), is heated by means of one or more electrical con- ,ductors constructed to form one or more per- ,manently closed circuits arranged within or c lose to, or so as to come close to, the exterior of the vessel and to form a secondary con- .ductor or conductors in which an alternating current is set up by current in a primary conductor wound upon a magnetic core that is adapted to receive or support,; oris' cornbined with the vessel, and to prod i ee in tthe .closed conductor 'or conductors, secondary ing such that when the apparatusjs in action and the vessel is placed within, upon or cembined with the magnetic core, the con tents of. the vessel will be subject to the heat produced by secondary currents inductively ,set up in the closed conductor or conductors. Such conductor o r conductors is tor are-herek Qinafter referred to as the electrical heater.

As in such apparatus considerable diflicultyg would. be experienced in effecting good con- When the electrical heater is placed with the magnetic coreanay be adapted to admit of the insertion, or partial insertion, of the :yessel therein sothat upon placing the. vessel n the core whenthe apparatus is in action, so as to bring the .electrical'heater withinthe' magnetic field of the core, heat will at once be produced electrically in such heater, and upon removing the vessel fromthe core,

heat will cease to be produced in the elec- Patented Aug. 2a, was).

V currents of low voltage, thearrange nent bein or attached to the exterior of the vessel,"-

trical heater, the apparatus being left on open circuit, so as to minimize Waste of en'- ergy, shouldt have been left in actlon. The

electrical heater may be fixed in-or be removable from the-vessel-and be in the form of one or more continuous metal rings or frames that may be arranged one Within or above the other and be bare, or be covered with suitable material,for example enamel,

to admit of the heater being readily-Washed and kept clean. V

The magnetic core may be constructed in various-forms to suit the vessel to be heated. Conveniently it maycomprise a numberot laminated 01' solid iron plates each con1pr1sing vertical and lower horizontal members, the several plates being arranged vertically and radially or otherwise so as to' form a star or other shaped group, as seen in plan, having a circular, oval or other shaped re- :c'ess between the several vertical members for the reception of the vessel the contents of which are to be heated electrically. The lower members of the plates may be pro vided with upward extensions to form recesses for the reception of the primary winding of the apparatus which then rests within the recesses and upon the lower members. Or the vertical members may be provided at their upper ends with inward extensions to form vertical recesses for the reception of a vertically arranged primary winding. The core may however be constructed as an iron casting in one or more pieces. The vessel may with advantage be provided internally with one or more iron devices of H or equivalent section arranged to form, in conjunction with the portion of the core outside the vessel, a more or less complete' magnetic circuit inclosing the primary winding and electrical heater. Conveniently a sin le removableiron device may be used for t e purpose just mentioned, such "device comprising for example, a circular, oval or other shaped plate formed with diverging slots and having. a downwardly extending central portion to rest upon the bottom of the vessel. Such a device may be an iron casting.

In theac'companying illustrative drawings, Figure" 1"shows in vertical section on the line A A of Fi 2, and Fig. 2 in horizontal section on t e line B B of Fig. 1, one construction of electric heating apparatus according to the present invention. Fig. 3 is a plan of the magnetic core shown in Figs. 1 and 2, the other parts being removed. Figs. t to 10 inclusive are similar views to Fig. 1 showing parts of modified constructions of electrical heating apparatus. Fig. ll'is a section on the line C C of Fig 12, and Fig. 12 is asection on the hue D D of Fig. 11, showing another modified construction.

Referring to Figs. 1, 2 and 3, the magnetic core forming the stationary part of the apparatus, comprises, in this example, a number of plates 1 arranged more or less radially (Fig. 3) with their flat sides vertical and each having an outer vertical member 1 and an inner vertical member 1. The s aces between the outer members 1 may at vantageously be filled in with other vertical strips 1, as shown in Fig-'3, so as, in conjunction with the vertical members 1, to

forma laminated ring for the reception of the correspondingly shaped vessel 2 which is designed to contain the liquid to be heated or the substance to be "cooked. This vessel rests on the inner vertical members 1 and is held in position 'by the outer laminated rin 1'. 3 is the primary winding arranged in the lower circular recess formed by and between the members 1, l and 1 4 are cone centrically arranged metal rings that constitute the electrical -heater and are held in distance pieces such as radial bars or pins 4*. These bars or pins may be fixed, as by soldering or brazing, to the underside of the rings so asto support such rings at a distance above the bottom of the vessel and allow of liquid passing below them. The rings and distance pieces, which may be of copper, may be coated with material such as enamel, tin, silver or nickel to prevent them affecting the liquid to be heated or being affected by such liquid, and to enable them to be easily kept clean. 5 is a circular iron casting of double '5'? section resting upon the bottom of the vessel2 so as to extend over the secondary conductors 4 and complete the magnetic circuit of the magnetic core 1, l,

l", l, the said casting having therein a number of diverging slots 5 to allow of the material to be heated coming into direct contact with the electrical heater 4. 6 is an insulating base provided with a switch 7 for switching on and cutting off the supply of alternating current for the primary windmg 3.

As will be seen, the arrangement is such that when current is switched on to the primary winding 3 by the switch 7, then, upon placing the vessel 2 with electrical heater 4 and iron casting 1 1, secondary currents will be induced in 5 in the ma netic core 1, 1*,

the. electrical heater 4. that will heat the same, and the liquid 2 in contact therewith, and upon removing the vessel, current and consequently heat, will cease to be produced in the electrical heater 4 and very little energy will then be wasted in the combined primary winding and core.

Instead of placing the heater 4 inside the vessel 2, it may, as shown in Fig. 4, be secured to the exterior thereof. near its lower end, so as to extend around the lower edge to theside wall of the vessel, as shown in Fig. 6; or to the bottom of the vessel, as shown in Fig. 7; or to both the side wall and bottom of the vessel, as shown in Fig. 8.

Then the heater is outside the vessel, the apparatus may be provided with material 9, for example asbestos, to protect the core 1, 1 1", 1 and primary winding 3 from the heat setup 1n the electrical heater 4. The core may, as shown in Fig. 8, also be surrounded with material 10 that is a bad conductor of heat, to prevent loss of heat by radiation. When the electrical heater 4 is to be carried by the vessel, it may, as shown in Fig. 9 be arranged toform part thereof, say part of its side wall, or bottom, or both,'instead of being made separate from and. placed there in or fixed thereto. The magnetic circuit of the core may in this case also be closed by iron, as by a circular iron casting like 5 in the vessel containing the liquid to be heated.

In this example, the vessel 2 is of annular shape, and the laminated iron core 1, which may, as shown, he of rectangular shape and be formed of iron stampings, extends through the hollow center of the vessel 2 so as to surround the vessel and the electrical heater 1 therein, and is energized by the primary winding 8. The electrical heater, which is like that hcreinbefo're described and shown in Figs. 1 and'2, may be held down by rods 4* placed between it and the cover 2 of the vessel. 2' is a hole in the cover for charging the vessel with cold liquid, and

2 is a draw oil cock for hot liquid. 6 is a base for the apparatus.

In the modified arrangement shown in Figs. 11 and 12, the vessel 2 is of rectangular shape and has two of its opposite sides connected by a non-metallic tubular portion 2 through which the magnetic core 1 with primary winding 3 extends. The secondary winding 4, shown as several complete rings, surrounds the tubular portion 2 of the vessel, the primary winding 3 and the portion of the magnetic core 1 extending through the same, so as to be in direct contact with the liquid 2 to be heated.

When the electrical heater at is arranged within the vessel 2, as in Figs. 1, 2 and 3, and in Figs. 10, 11 and 12, the said vessel may be constructed of various materials but preferably'of non-metallic or non-conducting material, for example stoneware, glass,

and the like. When the electrical heater is external to the vessel, as in Figs. 4; to 8 inelusive, the vessel, or part thereof, should be made of good conducting material such as metal.

1 The apparatus may, as shown in Fig. 6, be provided with a switch having a fixed contact 11 and a movable spring contact 12 so constructed and arranged, as shown, that the latter contact will be moved, as through a non-conducting plunger 13, into the closed position to close the circuit. of the primary winding 3 when. the vessel 2 is placed in position in or on the core, and will automatically move into the open position, to open the circuit of the primary winding, when the vessel is removed.

Heating apparatus of the kind hereinbefore described may be provided with means whereby the degree of heat can be varied from time to time to suit requirement, so that, for example, a high degree of heat can be produced for rapidly raising water or other substance to the boiling point, and a less degree of heat for maintaining it at or near the boiling point or at a lower temperature. Various means may be provided for this purpose. 1

In Fig. 10, the winding 3 is made in two sections arranged one abovethe other, the upper section having its ends connected to two .fixed contacts 3" and 3 and the lower section having its ends connected to two fixed contacts 3" and 3 of a switch device having two insulated movable arc shaped contacts 3 and 3 that are carried by a switchlever 3 and arranged to work over the said fixed contacts. As will be seen, the arrangement is such that when the switch lever 3 is in the position shown in full lines at a, the two sections of the winding are connected in series for minimum heating, and when it is moved into position I), both sections will be connected in parallel for maximum heating, the circuit of the windings being opened in passing from one position to the other. The sections of the winding will be connected in the reverse order when the switch lever is moved'back into the original position.

In the construction of apparatus shown by Figs. 11 and 12, a supplementary winding 3 adapted to act as a choking coil, is wound on the lower limb of the magnetic core 1' as shown in Fig. 12 and connected, with the main winding 3, to the fixed contacts 3 3 of a switch device having a movable contact 3 carried by a switch lever, 3. One end of winding 3 to one of the electric supply leads, and the lever 3 to the other lead. The arrangement is such that when the switch lever is in the position a the main winding 3 is in circuit and the supplementary winding 3 is out oi circuit so as to enable themaximum degree of heating to be obtained, and when the lever is moved into the position shown at 6 both windings 3 and 3 are connected in series with each other so as to allow of a lower degree of heating bemg obtamed in an ecoofthe apparatus may, as hereinbelore mentioned with reference to Fig. 9, be adapted to also serve as the secondary conductor or part in which the heat is to be produced electrically by the inductive action of the primary winding, a separate secondary conductor or conductors being used, or not, as may be desired.

y In each of the arrangements hereinbefore is connected through a switch 8 described, it will be seen thatv the part thereof in which heat is electrically produced is not in metallic connection with the source of electric supply, and that a currentof low voltage only is produced therein.

\Vhen heating zi ma iitris such as hereinbet'ore described is to be used in connection with a direct current supply instead of with an alternating current supply, means, such as an interrupter, is provided tor causing an intermittent, pulsating or nndulatory current to pass through the primary winding 3 ol the appa 'atus. Such a current is intended to be included in the term alternating current used in the foregoing description.

As will be obvious electrical heating apparatus and heating vessels or devices embodying the invention hereinbefore set forth, can be constructed in various forms other than those shown, to suit different requirements.

lVhat I claim is 1. Electrical heating apparatus comprising a magnetic core having a closed magnetic circuit, and primary and secondary conductors arranged in close proximity to each other throughout their length and to surround a part of said core, said. secondary conductor being permanently closed on' itself and arranged to be exposed throughout its length to the body to be heated.

2. Electrical heating apparatus comprising a magnetic core having a closed magnetic circuit, a primary winding surrounding a part of said core, a low voltage secondary conductor constituting a single turn of solid metal permanently closed on itself, arranged in close proximity to said primary winding, surrounding the same part of the magnetic core as said primary winding and arranged to be exposed throughout its length to the body to be heated.

3. Electrical heat-ing apparatus comprising a magnetic core, a primary winding thereon and a secondary conductor consisting of a single turn of metalpermanently closed on itself and of substantially uniform cross section throughout its length, said secondary conductor being arranged in induc tive relation to the primary winding and so as to be exposed throughout its length to the material or body to be heated.

4. Electrical heating apparatus comprising a primary winding, a vessel. to contain the material or body to be heated, and a solid annular secondary conductor of nonmagnetic material permanently closed onitself and arranged at the lower part of said vessel and adjacent to said primary winding so as to be under the inductive action thereof.

5. Electrical heating apparatus comprising a primary winding, a vessel to contain the material or body to be heated, and a solid secondary conductor of non-magnetic mateing a magnetic core, a primary winding thereon, a vessel'to contain the material or body to be heated, and an annular secondary conductor consisting of a single turn of nonmagnetic metal permanently closed on itself, said secondary conductor being arranged at the lower part of said vessel and in inductive relation to said primary winding and so as to heat the contents of said vessel.

8. Electrical heating apparatus comprising a magnetic core, a primary winding thereon, a vessel to contain the material or body to be heated, and a plurality of annular secondary conductors having a common axis and each consisting of asingle turn of nonmagnetic metal permanently closed on itself, said secondary conductors being arranged in inductive relation to said primary winding and so as to heat the contents of said vessel.

9. Electrical heating apparatus compris-- ing a magnetic core, a primary winding thereon, a vessel to contain the material to be heated, and an annular body at the bottom only of said vessel and in which heat is generated electrically when the apparatus is in use and whereby the contents of said ves- 4 sel will be heated.

10. Electrical heating apparatus comprising a magnetic core, a primary winding thereon, a' vessel to contain the material to be heated, and a non-magnetic annular body arranged at the bottom only of said vessel and in which heat will be generated electi'icallywvlien the apparatus is in use, said body being arranged to come in contact with the contents of said vesseh 11. Electrical heating apparatus comprising a magnetic core, a primary winding thereon, a vessel to contain the material to be heated, and a low voltage solid secondaryconductor of non-magnetic metal permanentlyclosed on itself so as to form a closed circuit arranged in said vessel and in inductive relation to said primary winding.

thereon, a vessel to contain the material to be heated, and a low voltage solid secondary conductor of non-magnetic metal permanently closed on itself, arranged in said ves- 12. Electrical heating apparatus comprismg a magnetic core, a primary WII'IClIIIg sel, and in inductive relation to said primary winding and traversed by part of the magnetic core.

13. Electrical heating apparatus comprising a magnetic core, a primary winding thereon, a vessel to contain the material to be heated, and a plurality of secondary conductors each consisting of a ring permanently closed on itself and through which the magnetic circuit extends.

14. Electrical heating apparatus comprising a magnetic core, a primary winding thereon, a vessel to contain the material to be heated, said vessel having a tubular part through which said core extends, and a secondary conductor located in said vessel and surrounding the tubular part thereof and the portion of the-core extending therethrough.

15. Electrical heating apparatus comprising a magnetic core, a primary winding thereon, a vessel to contain the material to be heated, said vessel having a tubular part through which said core extends, and a plurality of secondary conductors-each consisting of a ring located in said vessel and surrounding said tubular part and the portion of the core extendingtherethrough. 16. Electrical heating apparatus comprismg a magnetic core, a primary winding thereon, a vessel to contain the material to be heated, and one or more solid low voltage secondary conductors arranged within said vessel and in direct contact with the contents thereof.

17. Electrical heating apparatus comprising a magnetic core, a primary winding thereon, a vessel to contain the material to be heated, and one or more solid low voltage secondary conductors arranged within said vesseland in direct contact with the contents thereof and consisting or each consisting of a single turn.

18. Electrical heating apparatus comprising a magnetic core, a primary winding thereon, a vessel to' contain the material to be heated, and a solid low voltage secondary conductor consisting of a single turn arranged in said vessel and in inductive relation to said primary Winding.

19. Electrical heating apparatus comprising a magnetic core, a primary winding thereon, a vessel-to containthe material to.

be heated, said vessel bein traversed by part of,the' magnetic core, an asecondary conductor traversed by said core and arranged to heat the contents of said vessel. I

20. Electrical heating apparatus comprising a magnetic core, a primary Winding thereon, means for varying the act-ion of said Winding, a vessel to contain the material to be heated, said vessel being traversed by part of the magnetic core, and a secondary conductor traversed by said core and arranged to heat the contents of said vessel.

21. Electrical heating apparatus co1nprising a magnetic core, a primary winding thereon, a vessel to contain the material to be heated, said vessel being formed of nonmetallic material, and one or more low voltage secondary conductors within said vessel and in inductive relation to said primary winding.

22. Electrical heating apparatus comprising a magnetic core, a primary winding thereon, a vessel to contain the material to be heated, a low voltage secondary conductor permanently closed 011 itself and arranged to heatthe contents of said vessel,

and heat insulating material between said which said core extends, and one or more metallic rings located in said vessel and surrounding said tubular part.

24. Electrical heating apparatus comprising a. magnetic core, a primary winding thereon, a glass vessel to contain material to be heated, said vessel having a tubular part. of glass integral therewith, containing said primary Winding and traversed by said core, and one or more metal rings located in said vessel and surrounding the tubular part thereof.

25. Electrical heating apparatus comprising a magnetic core, a primary winding thereon, a glass vessel to contain material to be heated, said vessel having a tubular part of glass integral therewith, containing said primary Winding and traversed by said core, one or more permanently closed metal rmgs located in said vessel and surrounding the tubular part thereof, and means for varying the inductive effect of said winding on said rings.

26. Electrical heating apparatus comprising a magnetic core having a closed magnetic circuit, a primary winding thereon, a vessel to contain material to be heated, and a hollow secondary conductor of non-magnetic metal arranged at the bottom of said vessel and surrounding said primary winding, traversed by said core and arranged so as to heat the contents of said vessel, substantially as hereinbefore described.

Signed at London England this twenty-' 

